Audi S4 Case Study – Multiple ailments and a host of suspects

Troubleshooting faults in a workshop is rarely a dull moment whether you’re a newbie, beginning your deep-dive journey into modern vehicle fault assessments, or a seasoned pro who thinks they’ve seen it all. I am sure some of you readers can sympathise – my mind can sometimes wander, and I’ve been known to have the occasional brain fart, varying from slight to beyond moderate on the scale!

In preparation for the latest job to enter the workshop I read the job card the night before and made sure to have a brief conversation with the customer at drop off to get a better insight into the reported symptoms.

It was at the point of questioning the customer I felt one eye become ever so slightly lazy, picturing myself wearing a shaggy beige raincoat chewing a cigar and thinking about the ‘case’ in front of me – for those of you old enough to remember, and cherish, the memories of Columbo, detective extraordinaire. The irony here is that I floated the concept in my last piece

for AT that ‘we are analysts more than technicians.’ In some respects, we’re just as much detectives in the case of fault troubleshooting, which I think for a lot of us is the grit that keeps us doing what we do, to a good standard, day in day out. I digress….

Gareth found a useful collection of TPI’s all relevant to random alarm siren activity with no other DTCs stored.

The vehicle in question is a 2017 Audi S4 and had been in with us four weeks previously for a replacement battery. I had not paid much attention to the car in question at its previous visit. The customer’s concern was that the Stop Start system was not working and it never seemed to kick in, the A with a line through symbol would appear frequently when warm, but no matter what the circumstance or length of drive, it did not work. Furthermore, he asked us to investigate the heated rear windscreen not working on cold mornings, but the mirrors cleared quickly when the button was depressed. He also added an additional concern of reporting the alarm going off intermittently.

I began to consider the outcomes and fault patterns whilst ODIS was doing its thing conducting a full vehicle scan. Tool choice here was natural given I wanted to look at some key pieces of data and check a function had been conducted post battery replacement. Alarm triggers were going to be my go- to for the one customer concern, quiescent current analysis (battery replacement history, type, serial no, A/H) the next, and rich live data for the rear window concern. I had already created a 3-stage hit list, but I’d also reminisced of previous learnings on jobs and the importance of vehicle behavior patterns when it thinks one thing and is actually another.

In terms of stored DTC’s, there was not a lot to go on, 1- Alarm triggered, and that was it. Where to next? There was no guided fault finding or test plans created because there were no DTC’s. My next port of call before having my sacred brew and read was to put some more meat on the bone. It was unlikely in the time I had that I would get the alarm to misbehave going on the very intermittent frequency reported by the customer, but in terms of a quick road test (car was already warm from drop off ) I set off to observe Stop Start activity, and then a quick check of the rear window heater being switched on at the climate control panel, and a thermal camera to definitively confirm mirrors working, rear window not. The outcomes were as described, Stop Start did not work when I expected it should and the mirrors got toasty within a matter of seconds, with no sign of the window doing anything at all. With the faults confirmed, it was time to take a brief pause to do some research. I set about the following hitlist checks as a baseline start:

• Any TPI’s (Technical Product Index) relevant to any of my fault patterns?

• Current flow diagram of the rear window heater (note the setup is different for Avant and saloon so be careful, and in addition the Germans call it a rear window defogger, remember those search term definitions!)

Ensure data is the latest revision

The information search was useful. I fished a collection of TPI’s, see image above, all relevant to random alarm siren activity with no other DTCs stored, this bulletin has been updated several times. A TPI can have multiple revisions which is useful, but it can mean you come unstuck later if you are not reading the latest revision, as the guidance, or more importantly the SVM code, may have changed. The fix for the alarm was a Body Control Module software improvement, and had been through multiple changes, notably changing the SVM code for use within the ODIS SVM function, every time. I accessed the TPI through Alldata and the SVM code did not work. I rechecked the TPI’s within ODIS and then noted the latest change to the SVM and it applied correctly. Worth remembering when evaluating data and information, if in doubt, send a ticket as it may have changed in a short period of time and could leave you puzzled when you knew you were on the right track.

I was able to locate a current flow diagram, see below. Note the Asterisk marks that refer to a number code, advising on difference between model variants so you can follow the correct path for the control and wiring. I did not, however, yield a result on any relevant Stop Start issues.

Current flow diagram of the rear window heater.

Heading to the car it was time to begin some actual ‘doing.’ First port of call was the Stop Start issue. I headed straight for the battery management side of data. The reason being, I had pinned hopes on the battery replacement we had conducted potentially not being ‘registered’ in the car’s control unit, so it was still thinking it had a discharged poor state of health battery fitted. If this was the case it would validate the Stop Start issue without further troubleshooting, but in addition, may shed light on the rear window issue. ‘How so?’ I hear you cry. Well, little did I know some years ago, I had to investigate a rear window ‘defogger’ not working on a BMW 1 series 5-door hatch back. I ‘dithered’ away hours on drawing a blank on wiring checks, covers and trims off, checking this, checking that, to find that the car had the impression a poor state of health battery was fitted. I found this info eventually and checked the battery state of health data according to the IBS (Intelligent Battery Sensor) control unit log. The car had already had a new battery fitted a few months before being presented to me for troubleshooting. I registered the battery and low and behold, button depressed, windows getting warm! What?! Logical when explained and researched. Battery charge preservation becomes essential when the vehicle

(control supply) side of the circuit. One quick test and much of the circuit confirmed as good. Things then got a little more interesting. There appeared to be a ‘suppressor’ in the circuit, likely to reduce the effect of a high current consumer affecting something else in the rear screen when the high current consumer is activated. I checked the literature again, confirmed the rear screen was a busy affair, not only having the heater element, but also the antenna for the radio embedded within it. Further reading stated on my variant that there was a window suppression unit on the NSR D Pillar and a radio suppression unit on the OSR D pillar. With the NSR D Pillar off I confirmed the location and fitting of the suppression unit. Interestingly, at this stage, my sleuthing nature noted the presence of filler dust and body shop hallmarks, and rechecking in the NSR quarter area where the relay was located, there were also hallmarks of a previous repair. Now I’m not paid to judge, or spoil people’s days. The repair seemed adequate, but it did add an extra element we should always be mindful of when troubleshooting – human interference and disturbance.

The control relay was easy to access and test.

Human error

At this point I continued with my test plan. What’s happening at point B (the screen element connection) and what role is the suppressor playing? Above, you can see my test light showing a healthy voltage coming into the suppressor, confirmed by the meter, see below, right, and bright test light, but I had
no output at the screen just a stone’s throw away from the suppressor. I took the unit off given it appeared at the previous epicenter of damage/body repairs, checked resistance in preparation for a load test of the suppressor prior to ordering a new one (which at this point I had already found on the parts catalogue and was priced at a very reasonable £12 direct from TPS). My picture shows, I had failed to identify the fitment was incorrect, probably at rebuild stage by the body shop. The output wire for the rear screen was fitted to the centre bolt hole to hold the suppressor to the pillar, and not the output + terminal (ironically marked on the suppressor). No wonder it did not work. I moved the wire connection and cycled the window heater. Dew Dew (pun intended), on a thermal camera the window is now working! Stupid is as stupid does. The reality is this was as honest a mistake as the individual made when rebuilding the car in the first place. But it does show you have to have your mind in the zone and your wits about you when assessing faults. Test and check everything relevant, and always stop to reevaluate where you where, are, and plan to be within the task/process.

I smiled on reflection, and out of curiosity load tested the old and new suppressors. I had differing results so opted for the menial cost to advise and supply the replacement regardless of findings and despite proving the original could work. But nonetheless a useful learning, followed by the warm inner glow that I got the right culprit, I could leave on a Columbo quirky cliché and ‘limp’ off into the sunset. In reality it was pop to the loo with sheer excitement and collect the next job card!

I like documenting my tales and findings from the real- world workshop, as much as I like reading those from other like-minded technicians case studies. We need to keep up the fight, to research, understand, test and be confident in a job well done. Keep going, and never stop being the best you can be.

Save the Date! Big Weekend returns to Warwick this autumn

autotechnician will bring a group of technicians, workshop owners, trainers and aftermarket suppliers together again this September to share ideas, inspire and have some fun whilst learning about emerging technology and new opportunities at Delphi Technologies’ training workshop in Warwick.

Job-useful, practical advice will be on the agenda for tackling the latest systems and vehicles, without forgetting the vital theory and knowledge of the fundamentals that underpin success. The event is designed for both technicians and workshop owners.


Visitors to autotechnician’s Ask the Expert’s lounge at the UK Garage & Bodyshop Event at Birmingham NEC June 8-9th will be able to meet experts and trainers presenting over the two days.

Head to the informal lounge area, Stand G36 – a stone’s throw away from the EV & Hybrid hub – and you can also try out autotech’s online assessments – both new and existing users who log in and take the new test, or another multiple choice quiz from the online resource on the stand, will be entered into a prize draw to win £200.

Speak to a member of the team to also find out more about the Big Weekend training event in Warwick, taking place Friday 23rd and Saturday 24th September.

Both one & two-day subsidised tickets are available now at

Delphi Technologies new diagnostics

autotechnician spoke to Delphi Technologies about its new diagnostic device that could be a real game-changer for workshops looking to enhance their diagnostic capabilities and ‘take the faff’ out of integrated security gateways.

Delphi Technologies has developed its latest diagnostic tool, the BlueTech VCI, to enable independent workshops to tackle maintenance and repair tasks that would otherwise be passed on to a dealer or diagnostic specialist – featuring integrated DoIP, security gateway, ADAS calibration, and Passthru support. The DS180/480 (without/with a tablet) also provides support with trouble codes with its DTC Assist – guiding technicians though fault-finding procedures thanks to a database of thousands of real-life workshop repairs and displays expected live data values on screen so you know what to test and what results to expect. It gives the probable causes of over 1,700 fault codes across many marques.

The hardware on existing DS tools provides DoIP via an external adaptor, with the DS180 it is integrated, a third CAN channel has been added and this device is remote diagnostic compatible. A flight recorder enables you to perform a one-man road test; by selecting your parameters and hitting ‘Record’ you can review the data when back in the workshop.

One of the biggest USPs of the DS180 is the integrated security gateway access. Since 2018, Fiat began producing vehicles with a new Secure Gateway Module, removing direct scan tool access from the OBD-II connector for any of the networked modules not related to OBD-II emissions, restricting maintenance and repair functions. Upon clearance with the VM, normal duties can resume, such as clearing fault codes and resetting service information, component activation and programming adaptations. Workshops must sign up with each manufacturer and pay each of them, each time access is required. With the BlueTech VCI, Delphi plays the middleman – by purchasing a one, two or three-year license, authorisation is automatic, and you can open up as many gateways as you like within the Delphi subscription. Delphi’s Technical Services Manager, Phil Mitchell, told autotechnician: “It’s going to make life easier on so many levels. Technicians aren’t going to have to claim back any receipt claims (Phil has spoken to many technicians who are using their own money to fund gateway access as it’s too laborious to claim the odd few euros back each time), and you’re not going to end up running down a rabbit hole with a fault code…”

“Here’s the odd thing about fault codes, you plug it in and get a Cam sensor, you click ‘erase,’ and it won’t erase, and you don’t get an error. I said to our engineering team, surely, we can give an error message saying, ‘Software gateway locked vehicle, cannot erase.’ They said, here’s the weird thing, when you go to erase an error, if the car’s got a security gateway you get the same message back from the ECU as if it’s a permanent error. The ECU doesn’t know the difference, so the error message you get back from the diagnostic will just say I can’t clear the code, we can’t display anything as we don’t know if it’s a secure gateway or not. I said that could be a potentially big problem for people who don’t have a DS180 or something with automatic gateway because you get a cam sensor fault, go to clear the code and it won’t, so you think that must be a permanent fault, let’s go work on that problem.”

Introducing Mega macs X – the powerful, flexible and future-proof diagnostic solution

mega macs X from Hella Gutmann is an innovative, feature-rich and flexible diagnostic solution that allows independent workshops to keep pace with the continual advances in vehicle technology, whilst also safeguarding against the rapid rate of obsolescence that often affects conventional diagnostic tools.

A range of software options and accessories ensures the mega macs X provides the optimal diagnostic solution whatever your workshop requirements may be – now and as your needs grow.

Find out more about mega macs X

Putting the power in your hands

Mega macs X connects wirelessly to your chosen external display and input device, whether a tablet, notebook or PC running Windows, Mac OS, Linux or Android.

Each software module offers varying degrees of functionality, from basic features to advanced capabilities. Simply choose the appropriate software module for your workshop’s current requirements and upgrade easily at any time, so you only pay for what you need.

Powerful, capable and built to last

Boasting futuristic looks, mega macs X is also designed to be compact and robust, to meet the demands of busy workshop environments.

Clever design features include a built-in bracket at the rear of the device allows the mega macs X to be easily attached to a vehicle window when in use, the OBD plug has an integrated flashlight that makes it quicker and easier to connect the device to the vehicle, and inductive charging reduces the number of cables.

On the inside, state-of-the-art processing power enables lightning-fast diagnosis and repair, and the very latest communication interfaces, such as CAN FD and DoIP are supported.

A dedicated range of accessories

The optional Hella Gutmann Tablet is a powerful Android tablet designed specifically for the mega macs X, with a focus on maximum speed and efficiency, whilst allowing diagnostic reports to be sent directly from the tablet.

It comes with a shock-proof casing and a docking/charging station with HDMI and ethernet ports for the connection of other devices.

Two optional Measurement Technology Modules enable the mega macs X to be used as a practical two-channel multimeter. Suitable for use with hybrid and electric vehicles, the MT-X enables precise measurement of voltages up to 1000 volts DC, while connecting wirelessly to the mega macs X via Bluetooth for added convenience.

Key features:

Click here to request a FREE demonstration or call Hella Gutmann on 01295 662402

Case Study: Misleading fault codes on a SEAT Ibiza

By Des Davies AAE MIMI,

Top Gear Motor Services

Vehicle: Seat Ibiza 1.4 16V 2008, mileage 75,546 Symptoms: Fault code PO322, stalling & non-start

A customer brought their 2008 Seat Ibiza into the workshop, complaining that the vehicle had started to play up recently, it would stall then crank over but not restart. After allowing it to cool down for 30 minutes or more, the engine would start but not rev up, there was no power and it would stall again. When, eventually, it did start up once more it would run normally. This had happened on two occasions and the customer was now frightened to go very far but needed to use it for longer journeys as he was off to university.

This vehicle had been ‘diagnosed’ and checked over at different garages who suggested that the fuel pump and ignition coil needed replacing and they had fitted new spark plugs. No other previous work was disclosed by the customer.

I first checked inside the vehicle to see if the check engine light was displayed on the instrument panel when the engine was running, but there was no warning light present, and the vehicle was actually running well.

My next job was to conduct a road test and attempt to recreate the faults, but the vehicle performed really well and displayed none of the symptoms the customer was complaining about.

I then connected my scanner to the OBD connector to check for any fault codes to help me with my diagnosis. There was a fault code PO322, which I was interested in, and a fault code for the ABS system and central locking codes.

Common symptoms for code PO322:

• Engine misfire
• Engine stumble
• Lack of power in the engine
• Engine hesitation
• Engine cranks but will not start.

Sounds familiar to me, so let us have a look at some of the possible causes for this code:

• Open in control circuit (ground circuit) between the distributor/ignition/engine speed sensor and PCM

• Open in the power supply circuit between distributor/ ignition/engine speed sensor and PCM

• Short to ground in power supply circuit to the ignition distributor/ignition/engine speed sensor

• Faulty ignition, distributor, or engine speed sensor.

Other possible causes:

• Defective crankshaft position sensor(s)
• Defective camshaft position sensor(s)
• Corroded or faulty crankshaft position sensor(s) connections or wirings
• Misfiring engine • Rough running • PCM fault.

Checks for anomalies

I then used my scanner to check the live data Parameter
IDs, PIDs, to see if anything stood out, but all looked OK. The fuel trims were good and there was no evidence of ignition misfires. The 4-gas analyser was then inserted into the exhaust tail pipe – this is a quick and easy test I like to do to check for any anomalies and to see the burning of the air/fuel mixture at idle and cruise in the combustion chambers. For a 14-year-old vehicle, it was running well.

Idle – CO 0.8%, HC 170ppm, CO2 1410%, O2 0.8%, Lambda 1.03λ

Cruise – CO 0.3%, HC 90ppm, CO2 1420%, O2 0.3%, Lambda 1.01λ

It was now time now to work smarter and not harder and plan a diagnostic testing method to help me identify the fault, or faults, within this system. I decided to get some technical data to familiarise myself with the system and circuits involved and to set up a plan of attack.

I was looking for the easiest and best system component to do a non-intrusive test – a good starting point of my diagnostics. I decided to check the crankshaft sensor output using my PicoScope as I thought that this would be an easy sensor to locate and check. However, I discovered that this sensor was at the back of the engine and the access to the connections was awkward.

I could not physically or visually see the crank sensor, so I decided to check the sensor at the ECU, which was located at the bulkhead near the battery. It was fairly easy to connect my test leads. I referred to my technical data to find the pin no’s 82, 87 and 108 for the crankshaft sensor, which were yellow and grey wires and brown/blue at the engine ECU. See Figure 1.

I tested the crankshaft sensor, see Figure 2, then tested the camshaft sensor. This was located on top of the engine and was easy to access, Figure 3 shows this waveform. Both these sensor outputs were good. I then ran the engine for a while to check for dropouts with the two sensors on a longer time base, but all was well, so it was time to have a think about the next step.

Figure 1: I referred to my technical data to find the pin no’s 82, 87 and 108 for the crankshaft sensor, which were yellow and grey wires and brown/blue at the engine ECU

I could check the sync of the cam and crank sensors to try to get a known good sensor reading, but I did not have one in my own library. I could research online for a known good sensor synchronisation or perform an in-cylinder test, but as the cambelt cover on this vehicle is easy to remove, with only two clips on the top cover, it made sense to check this first (thinking smarter not harder).

Figure 2: The crankshaft sensor waveform was good

On removing the top cover, I shone my hand held light down towards the timing belt and could see the guide pulley and its plastic surround had disintegrated and was probably lying at the bottom of the engine near the crankshaft sprocket waiting to do some damage! I could get my hand down onto the timing belt and move the belt, I felt a lot of play and slackness in the belt, indicating that the valve timing must be out.

At last, I had found the problem! The camshaft timing was allowed to move out of sync with the crankshaft, moving the valve timing away from manufacturers specifications, and therefore causing the intermittent issues – where was this in the fault code description? Do not always rely on fault codes as they will bite you on the arse and I have previously had big teeth marks there, painful, and embarrassing! This vehicle needed a new timing belt kit complete with guide pulleys, tensioner, water pump and auxiliary belt.

Figure 3: The camshaft sensor waveform also proved to be good

I have had a few problems with previous vehicles that have either a cam or crank sensor fault codes and whilst testing these systems they have displayed good waveforms, but when you check both together on the oscilloscope against a known good sensor waveform, they have had cam/crank sync problems, indicating valve timing issues. One example was a vehicle that had been fitted with three, yes three, new cam sensors by a local garage as the check engine light kept being displayed after replacing the camshaft sensor. They assumed that they were faulty sensors! The previous garage had been road testing this vehicle after fitting each camshaft sensor with a broken tensioner and flapping belt, how lucky were they! This had been going on for a few weeks.

In summary
Fault codes can be misleading. You can end up chasing your tail and you may start playing parts darts, which is no good for the customer or your reputation.

I have some customers asking me to check their vehicle for fault codes when the check engine light appears on the dashboard, they then want me to give them the codes so that they can repair the vehicle themselves. This does not work.

Some customers believe that I can tell them what the problem is with their vehicle just by reading the fault codes. I have to be very diplomatic with them and explain that I need to test the vehicle systems and components to help diagnose the faults, you just cannot fix vehicles going by what fault codes have been retrieved.

Trust your knowledge of basic systems, your testing methods, tools, equipment, and always think outside the box. If you are not sure of your testing results, test again using a different method and test equipment, go back again and revisit your last previous test to see if you have missed something.

We are all under pressure with time and workload, the customer always asks how long it will take to fix the car before you start diagnosing the problem. It is very easy to rush and make mistakes, I am guilty of this myself.

Training and learning are essential! As is having the right information and vehicle data to help you fix the vehicle. Knowledge is power!

Autotech – Flex your tech skills in 2022

Now in its sixth year, autotech has provided technicians with the means to assess their knowledge and diagnostic process using free, online assessments, and delivered technical information to address any shortfall within autotechnician magazine, online and digital media, at its live ‘Big Weekend’ training events and via its autotech online technical videos on YouTube.

An evolving bank of online assessments created by independent automotive trainers are available free of charge to technicians. Topics covered include: The Selective Catalytic Reduction system, Hybrid & EV technology, Testing electrical components,Oscilloscope use, Common sensors used in spark ignition engine management systems, LIN Bus, CAN Bus, as well as an ignition and diesel case study.

To access the existing bank of 14 tests, all you need to do is enter a few brief details about yourself at, we’ll verify your email address then you’re in! Simply log in if you have been previously registered.

The online test is completely confidential and you’ll receive your scores and correct answers to see the areas which you perhaps fell down on. Explanations of each answer are also provided. The online resource is refreshed regularly and will include questions for all levels of ability from those just entering the world of advanced repair to top techs.

Keep an eye out in the magazine and on social media for further incentives to take a quiz!

Can you crack the P0303 fault code?

Challenge your diagnostic process and system knowledge with our brand-new multiple choice autotech assessment available at The confidential assessment is presented as a case study, centring around the P0303 fault code. The questions are structured to reflect a real-life fault within the workshop and have been designed to examine your procedures, diagnostic tool use, in addition to your knowledge of gasoline direct injection systems and coil-on-plug ignition systems.

To access this new test, and a further 13, all you need to do is enter a few brief details about yourself at, we’ll verify your email address then you’re in! Or simply log in if you have been previously registered.

“ACtronics are pleased to be continuing our sponsorship with Autotech for 2022. As the market leaders in remanufacturing electronic automotive components, not only do we offer a first-class solution for garages, but we also support first class training and technical support for the automotive trade. It’s more important than ever for technicians to have access to world-class training and ACtronics are very happy to work alongside Autotech to provide this. It’s important that we all work together to futureproof garages ready for the changes ahead.”

“Blue Print and febi are thrilled to be sponsoring Autotech again in 2022. We understand the pressure on technicians to keep ahead of the ever-changing world of vehicle repairs and components. autotech allows us to share technical information directly with the best technicians in the industry, enabling them to stay one step ahead and continue to provide efficient professional repairs.”

“Delphi Technologies is delighted to have renewed its sponsorship of Autotech in 2022. As a pioneer of OE technology, we are in the perfect position to support technicians through the new challenges that they are facing. Whether it be the servicing of hybrid and electric vehicles or the calibration of ADAS components, Delphi Technologies offers the training, diagnostics, and technical support to guide technicians through the challenge.”

“Sponsoring Autotech is a perfect fit. JLM Lubricants’ products, including the pioneering DPF range and professional DPF cleaning toolkit, have been developed for the trade, are tested by the trade and supported with technical information and training via the JLM Academy plus the extensive suite of online training videos – created by mechanics working in a diagnostics’ driven environment. Contact Kalimex UK distributors of JLM products for anything JLM related, including technical questions and training.”

“VARTA Batteries are delighted to be sponsoring Autotech once again in 2022. VARTA the world’s largest automotive battery manufacturer works closely with nearly all vehicle manufacturers to supply their batteries as original equipment. The very same batteries are delivered into the aftermarket, so when replacing the original battery with a VARTA, you can be sure it’s a like-for-like quality. The team at VARTA will be on- hand at Autotech’s Big Weekend later this year to discuss the latest developments in battery technology.”

autotechnician will bring a group of technicians, workshop owners, trainers and aftermarket suppliers together again this September to share ideas, inspire and have some fun whilst learning about emerging technology and new opportunities. Content will also be devoted to the fundamentals that underpin success.
If you would like to know as soon as the dates are confirmed and one & two-day subsidised tickets are available, simply email
autotechnician has created seven technical videos with the help of Andy Crook, Darren Darling, HEVRA’s Pete Melville, Matt Cleevely and autotech sponsors. These include presentations on scoping techniques, EV thermal management, ADAS recalibration, preparing for EV business, battery testing, wheel bearing replacement and DPF issues.
Search forautotechnician magazine on or visit the channel directly on

A five-stage process from fault to fix

Following on from his presentation at autotechnician’s Big Weekend in November, Gareth Davies provides a recap and expands on the benefits of having a process when it comes to assessing vehicle faults in the workshop.

Data is defined as individual facts, statistics, or items of information (often numeric). In a more technical sense, it is a set of values of qualitative or quantitative variables about one or more objects. The statement I put forward to the audience at the Big Weekend event was ‘We are analysts more than technicians.’ My question to you is, do you agree? If you don’t, perhaps you will by the end of this article…

In days of old I think we can all agree our eagerness to be doing (as technicians by very nature we are doers) has dictated the path and flow of our regime when approaching a troublesome vehicle. What I mean by that, is that a tool of choice is selected from the point at where a vehicle is brought into the workshop, in preparation for the doing part (figuring out the problem). This event for a long time may well have been totally autonomous and dictated by tool availability, it may have been relevant to the reported symptom, or it may have been that we always ‘do diagnosis’ this way. The phrase ‘diagnosis’ by the way is not limited to warning lights on the dashboard or a rough running engine… If you stop and think about it, that’s the preconditioned autonomy happening again, isn’t it?

Diagnosis is undertaken on anything that does not work correctly, does not work as it did (usually after you serviced it but 8 months later!) it could be a noise, a symptom. So, diagnosis, in effect, isn’t the culture that’s been bred of ‘plugging in’ and to be doing. Diagnosis is taking steps back to how it was done way before OBD and taking a note or two. We are all aware of the variety and proposals out there from garages for diagnosis, or as I prefer ‘Fault Assessment.’ For example, you can get diagnosis for free in some garages, others may charge a set fee for a ’plug in’ or it may be by the hour, it may be a different hourly rate depending on whether the special computer has to come out! Should you be charging less or more than the garage it came from are because they advocated your services due to having a ‘better computer’? However you decide as technicians or business owners to market this service, explain its functions and decide on time provision is entirely down to what works for you and your business. But and there is a significant but, when you have understood your offering/pitch, then you have a start point for your diagnostic process. This is the reason the diagnostic process really begins before you’ve even met the customer.

At this point, some of you may be saying ‘I’m a one- man band/a small garage, process sounds long-winded and difficult or needless to implement.’ It need not be difficult… Most of you, whether you identify it or not, will have a process to some extent, and now would be a good time to stress test or review it.

Your offering: This should be clear and concise, staged, and progressive, and represent value for money for the customer and the business. There is no such thing as a free lunch in life so how accurate and detailed will the free diagnosis be? Well, short lived in business terms if it covers those bases and does not make it up in the repair structure. Some people offer this service, we used to in fact. Why would you though? A business requires reinvestment for training, tooling, and development. Fault assessment should always be charged for, regardless of repair structure and outcome.

‘Plug ins’: How much value is here for the business and the customer? It may be a decent return for one party but not the other. Consider this method redundant. It will lead to inaccurate hypothesis on what’s wrong and will leave the customer wanting. Reading faults and issuing a printout in my opinion no longer has a value. Its robotic and yields little to no result. Identify your customer at the enquiry stage as to whether they seek conclusions. This may be less of a challenge for regular customers or have previously been through the process, but for new custom opportunities, this is a great way to set the stall out early for what your process offers, and what they may gain for the appropriate fee.

Appropriate fee: This is variable and dependent on geography, tests to be carried out, approach, previous success rate repute, previous investigation/interference by others etc. This may sound slightly uncouth, but we need to appreciate the talent value – the potential effort or challenge within the presented task and the value we may be offering. An example would be as crude as analysing my business’s fault assessment cost vs a local franchised dealer. In raw outlay, they are cheaper (GASP!) Does it mean we don’t carry out many fault assessments? Of course not. We have a shorter lead time, we do more than a franchise does for the fee, we have available loan cars, we use methods not used within a dealer (simulation/substitution) and we have better customer service. Whatever the reason, price has to some customers, but not all, become irrelevant. It doesn’t mean they are being overcharged or we’re taking the mick, there is just an underlying appreciation for what we do, how we do it, and so on. All of this stems from the diagnostic process.

OK so back to the nitty gritty. Establish where your process is or isn’t at. This is back of fag packet stuff and nothing more now. Set out bullet points that cover all that is to be achieved and what you may need to achieve this, such as resources, tooling, time provision and charges.

Step 1 Customer interrogation

This is vital. In order for you to solve the problem accurately, timely, and as ‘eyes wide open’ as possible, you need to spend some time with the customer beyond taking the keys from them at the drop-off point. This may be time we may not think we have or need, but I assure you it is time spent well here. Depending on the setup of the garage, it maybe you and only you, or it may be cascaded via front of house, workshop control etc. By creating a diagnostic questionnaire, you can fact find without too much effort. Populate a short form that includes all the questions you want answers to as a technician assessing a fault. Topic areas could include some/all or anything you feel relevant similar to the document Figure 1.

You can be savvy with your time and send these electronically by email before the scheduled appointment, so that data acquisition is already taking place before the job is in the workshop. It gives freedom for the customer to play their part in telling you as much as they can (urging them of the reasons why this will help everyone) and even if handwritten but scanned in by them or at point of drop off, it is great reference material. It is preferable to a quick chat at drop off when you can forget what they said, or it becomes diluted when passed from front of house to the workshop. If you have these clues before seeing the vehicle, you can already get the cogs turning in your analytic mind as to a ‘sportsman’s’ hypothesis on the area of concern. You can think on it if nothing more, but it can be really helpful.

Finally, this form is also rather useful for reminding of some basic, but often forgotten, customer prerequisites such as previous history (i.e., already had parts replaced), servicing state, minimum fuel level requirements for testing etc. How many of you bring cars in for testing and find the fuel light on or five miles to empty?

Figure 1

Step 2 Initial inspection, 10-15 minutes

We now take the opportunity to get the vehicle in, get a battery charger on and carry out an initial system scan of the vehicle. This can vary, some tools have quick boot and scan time, others, such as manufacturer tools, can take some time. Use the time wisely. Let the machine do its thing while you do yours. Have a quick walk around the car, check tyre condition, engine oil level, do a battery test (if easily accessible), visual engine check (obvious split hoses, serious oil leaks etc.) This is a great habit to get into, it uses the time to good effect and also helps protect you within your tasks. For example, you wouldn’t want to potentially carry out a road test with two bald tyres and engine oil level below minimum, for your own sake, other road users, and, most importantly, you may well compromise yourself or the business financially. Currently you have no measure of the health and integrity of the candidate. It may also include, depending on the nature of the fault, a pretesting road test, as for example the issue may solely be under driving conditions.

Once your systems scan is produced save it, print it (I recommend two copies – one for the customer’s record and one to work through, oil fingerprints and all). If you like
to do your bit for the environment, PDF it and log it in a folder of cases. You could then export all your findings and digital evidence onto a USB stick or create a cloud link for the customer. At this stage, I would advise to leave the vehicle as it is, unless something has turned up during the walkaround and quick visual, and pull up a pew with a brew for the next step…

Step 3 Information research, 10 – 25 minutes

This is often an overlooked and under rated step of the process. It’s back to the doer nature again. We can’t be sat around staring at a computer screen with a cup of tea in hand, can we? Why not? I consider this as one of the most vital steps in identifying: The area of concern; clusters or groups of faults; the number of faults present; and the relevance of the area of concern to the reported symptom. Does the reported symptom match the presented symptom? A tip at this stage is get some highlighters and highlight clusters that belong together. i.e., a lambda fault and fuel trim fault at this stage may be linked, but it will have no obvious relevance to a fuel

flap actuator circuit fault. Your testing will prove if even the most obscure faults belong to the same family of fault source. If they don’t, then you are laying the foundations for a thorough analysis of the vehicle’s issues and ensuring the analysis and repairs are profitable for the efforts that need to be applied. How many times did you fix the warning on the dash but were questioned why you didn’t fix the inoperative cigarette lighter as part of the repair?

Now, depending on the nature of symptoms and type of fault, engine running condition, warning lights, body electrical, this is where the path of this step takes many forms, with too many eventualities to cover. In terms of process, however, it’s the point at where you may research the fault code definition. This may involve the examination of current flow diagrams or researching technical service bulletins or known fixes. It may even be that the nature of the fault, its symptoms, and the known fix, hypothetically require services or intervention that you don’t currently offer or are capable of. Whilst not ideal, you can conclude this job, providing great insight to the customer with your findings. You cannot offer them a solution but can confirm the solution is X and will require Y to affect it. The value you sell even off the back of a no-fix solution, saves time, effort and unnecessary expense for you and the customer and, in addition, adds credibility to your repute for the transparency. Let’s say, for example, ‘the issue is currently solved under a warranty/goodwill measure from the manufacturer’.

If we have not fallen into the above scenario, and we now know where we are going to test, what we are going to test and what we are expecting to see as a result, then you can move on within your process. If you can’t confidently answer the above, now might be the time to do some on the job or just in time learning. This is equally as important to the end outcome for all parties. The reason being, if you are about to carry out some dismantling, or mild intrusion for testing purposes, you want to know how to be able to test the circuit or component, and what to expect from a bad or good result. Without this, you can fall into a rabbit hole, often born from (you guessed it) our ‘doing’ nature. Over the years, and hard learnings of wasted and improperly charged jobs, I have found 20 minutes researching for 10 minutes accurate testing, is worth much more in efficient work and results than 10 minutes ill-thought looking that becomes 4 hours, still with no result.

Step 4 On-vehicle testing, 15-30 minutes

You should now have a much clearer picture of the area of concern, the testing you are going to conduct, the component locations, the circuit layout, the testing conditions for the circumstance (freeze frame data states fault occurs at 3,000rpm and coolant temp of 84 oC, don’t carry out the testing at idle from cold), circuit layouts etc. This is the step that takes the wide spectrum and begins to narrow it right down. It must do this, even if for multiple fault symptoms or areas of concern, otherwise you will not be efficient in accurate testing that creates measurable validated results.

An example that springs to mind would be a Mk5 Golf indicator problem we troubleshooted a few years ago. It had been to a few garages and some testing had been carried out but to no root cause conclusion on the fault source.

The DTC stored in the BCM was open circuit/malfunction of NSF indicator bulb. The bulb was a simple 21W filament bulb, and we confirmed it did not light up when the indicator stalk or hazards were on, and the increased flashes per minute were present when actuated. In addition, a bulb telltale would reset with ignition cycle until the light was actuated again. The only check carried out at this stage was the bulb integrity, which was confirmed as new, intact, and fitted correctly (Step 2 stage).

The wiring diagram was checked, and test points were created. The first was at the bulb connection, back probing with a test light using a back pinning probe at the headlight, flipping to test positive and ground connection. No output was confirmed. The second test point was the source of the signal/ instruction, the BCM. Relatively accessible, the same test was carried out at the BCM and confirmed no instruction output. A wire test was carried out by isolating the wire from the plug at the BCM, and a load was driven down it. This crudely confirmed via a power probe (know when and where to use) I could make the indicator light up. We confirmed the fault as the BCM itself. Now we all have that feeling inside of, ‘wow a new BCM for one light circuit failure, it can’t be right?’ It was, and between the analysis, evidence and test results, the repair was authorised. The new part was fitted, and the fix was confirmed. The degree of nervous emotion when concluding a required repair becomes less when you can be sure of your testing, approach, and methods. The wobblier the methods, tests and results are, the less likelihood there is of a positive fix outcome.

At your testing stage, you may wish to validate your ‘finds’ by means of substitution or simulation. This could take the form of an overlay in the case of an electrical fault. Always remember to take the simplest approach to prove the theory. i.e., a broken wire has been highlighted somewhere between the bulkhead and the NSR quarter panel, buried in trims, covers and insulation that will take time to find. If the belief is the wire is compromised, you could run a back pinning probe and lead from point A to point B. This will not be pretty, or lasting, but it only has to be the proof of a fix. The labour that is required to create the repair will not necessarily be included as part of the assessment. A tip here is know your fundamentals. Be mindful of CAN Bus and how it works, be mindful of the size/gauge of a wire and its reason for being that size. I remember a vehicle from a very long time ago that had a wiring fault on a lighting circuit but kept blowing the fuse. The operator saw fit due to the inconvenience to u-bend a 4-inch nail to replace the fuse until it was fixed. Unfortunately, the fix in the end required a new dashboard, fuse box and wiring harness as a result!

Depending on the outcomes of your testing, it is another good point to begin thinking of the repair structure, and how suitable your offering is to the repair. For example, if a component is to be replaced (using the Mk5 Golf example above) does it require coding or a handshake to commission and complete the repair to a ‘fully fixed state’. If it does, between your offering or contacts in the trade, can you deliver a ‘fixed’ solution under your umbrella and be mindful of costs, so you are appropriately charging for these efforts and outsourcing?

Step 5 Repair structure

This stage of the process is important as the end of the assessment approaches, but the beginning of the repairs may commence. I am sure many of you operate only as diagnosticians, in which case, only proving rather than fixing is within your offerings. For those of you keen to secure and facilitate the fixing part (we’re doers so we’ve been gagging for this bit, right!) then you should begin by summarizing in reasonable detail, the process so far.

Your write up will need to consist of more than a single labour line detailing ‘Diag – bulb fault.’ The reason being is you’ve done so much more than that. This is not an exercise to over inflate charges, but it is a great opportunity to create proper detailed records for yourself and the team (they may have to look at another fault on this vehicle in the future) and it will also instill confidence in a great attention to the customers faults, how you have accurately pinpointed this issue, and know that following the outcomes of your assessment tests and methods they can have a high confidence in the proposed repair.

Now we all know that a small amount of solder, a piece of heat shrink and replacement of a 4-inch section of green crusty wiring isn’t going to pay the mortgage. Any repair should be charged for appropriately, but if you have been doing free diagnostics up until this point, the bills aren’t going to be covered. Most customers are rational and understanding. If the structure of what you are offering weighs up as value for money, charging for diagnostics should never be a question you have to ask yourself. Likewise, make sure that the repair is charged for accordingly. It may be quite labour intensive, it may be a collection of parts or processes, make sure the labour times and efforts required are researched specifically to vehicle application, and that any associated parts etc. are all accounted for as part of the estimate.

Project findings, and the evidence of the findings, in a clear and concise narrative. You don’t need to be the next Tom Clancy, or Danielle Steele, we’re technicians, but there has to be meat on the bone to summarise all that’s taken place.

Before submitting anything to the customer, just take another moment to analyse everything that’s been done. Have you covered the brief, are you making the customer aware of things you’ve found or discovered that may be incidental or unrelated to what they have presented the vehicle for? Are you as the technician satisfied with all you have done? Furthermore, don’t be afraid to engage with customers. We’re all mindful of time, it’s the only commodity we or the businesses we work within sell, but have you kept track of how much time you may have spent at each stage here?

There are variables sure, and I can’t cover every eventuality, but the above is a guide, food for thought even. Our way may not be your way, you may feel there is too much, you
may feel there isn’t enough. And the detail here is it needs to be about you, the business, and the customer. The process evolves, sometimes in minor detail and sometimes in a major overhaul. It’s been constructed as a team, over a long period of time. Some material and ideas are mine; some have been picked up from spending time with great technicians and great businesses alike, and the bits we needed have been taken out and fitted to our process. The process can be handwritten and laminated, it could be a note on an app on your phone, its not designed to be complicated, but it should be easily referenced, drawn on often, and improved as needed.

What I hope has been demonstrated above, is that you can sell your value and skills, you can offer great customer service, and you can also troubleshoot some faults,
all whilst earning a fair return for the efforts applied. I challenge you to evaluate your current process for assessing faults, and not by adding anything I’ve given you above, but can anything be improved from your or your team’s point of view? Can you add value, can you sell the value – ultimately, continued improvement is always better for everyone?

Electric vehicle training

Sitting on the fence when it comes to EV training was no longer an option for MY Motoring in Gillingham. Editor Nicola St Clair joins them for some on-site training to learn how to safely work on high voltage vehicles.

I have been taking my cars, and recommending my family and friends take theirs, to the independent, family-run workshop down the road for years. Brothers James and Michael Cameron and the team at MY Motoring in Gillingham, Kent have provided a professional, friendly service to customers in the area since 2005 but they recently lost my custom….

Earlier this year, I took the plunge and bought myself a 2017 Nissan Leaf, an investment to reduce my monthly outgoings and eliminate the considerable pollution I was adding to the local environment with my aging, gas-guzzling Saab 9-3. The Leaf is nippy on my local commutes and is as cheap as chips to run – with one home-charge costing around £4. But when it came to getting a major service and MOT last month I took the car to my nearest dealership, not something I have done before, as my trusted workshop down the road had not yet undertaken any hybrid or EV training but they have now rectified this!

As an LKQ Euro Car Parts customer, they tend to use its Auto Education Academy platform for their training, now relaunched as LKQ Academy, and a recent cancellation meant that the team could get booked in for an ‘IMI Level 2 Award in Hybrid Electric Vehicle Routine Maintenance Activities’ at short notice. So, I wrapped up warm and joined MY technicians Hassan Khreibani, Adam Tebbutt and Andrew Rowley at the local workshop for the on-site training. Pro-Moto Trainer Rob Usherwood delivered the day’s training on behalf of LKQ Academy, using his Toyota Prius, and my Nissan Leaf for comparison, during the practical tasks.

7 steps to make a hybrid or electric vehicle safe to work on:

  1. Duty of care to others: Ensure suitable signage is placed on the vehicle and restrict access prior to any work/tasks carried out on the High Voltage system
  2. Switch ignition off & place keys at least 3 metres away
  3. Disconnect negative terminal from conventional 12-volt battery
  4. Wear correct PPE
  5. Remove service connector/Switch main contactoroff
  6. Wait 5 minutes
  7. Check for voltages at HV Terminals

LKQ Academy can provide on-site training at your workshop.

The content of the IMI Level 2 Award qualification has been designed to give technicians the knowledge and skills required to work safely on Electric/Hybrid vehicles whilst carrying out routine maintenance and repair activities. The Level 3 and 4 Award that follow equip you with the know-how to diagnose and repair the high voltage components and systems themselves. For the morning’s theory session, Rob detailed the terminology, types of Hybrid & EV vehicle layouts and the arrangement of high voltage systems before we headed over to the Prius to identify the various components and considerations when performing maintenance tasks. Understandably, we then spent much of the time going through the 7-step safety precautions and procedures, with each technician performing the practical task of shutting the car down, proving it is safe and re-instating. A technical write- up on this process was performed as part of their assessment. Rob then provided details of the first aid required for the various potential hazards and gave an overview of Auto-Stop Systems and the construction and function of Hybrid/EV systems.

Rob unveils the HV battery underneath the Nissan Leaf

The final part of the afternoon session saw the technicians complete an online assessment, to ensure they had learnt the essential steps to ensure safe working around these high voltage systems. I am happy to say all three technicians passed with flying colours and are eager to complete the next levels of accreditation.

Thank you to LKQ Academy for supplying the training, Rob Usherwood and Pro-Moto for the perfect delivery, and to the fantastic team at MY Motoring for their eagerness to keep up with technology.

Investing in becoming Hybrid & EV ready…

There is a perception that becoming electric vehicle and hybrid-ready is a big financial commitment, but LKQ Euro Car Parts says that training and equipping your garage can cost less than you think and because specialist hybrid and EV servicing commands a high labour rate, a return on this investment can be realised quickly.

Approximately 6% of technicians in the UK are currently trained to support a market of more than 750,000 hybrid and pure EVs, so there’s a real opportunity for technicians who upskill now to set themselves apart from the competition. Hybrids are already fairly common in the independent aftermarket, with many in their fourth and fifth years of ownership. And EVs won’t be far behind.

Signing up for the LKQ Academy is free, and annual memberships start from £549 + VAT. With more than 30 locations in the UK and Ireland, LKQ Academy offers Level 2,3 and 4 hybrid & EV repair training courses, all backed by the IMI’s “Tech Safe” scheme.

The Level 2 course is the most popular, and covers routine maintenance activities and terminology, while providing technicians with a thorough understanding of the construction and function of hybrid-electric systems and outlining key safety considerations for working with high-voltage operations and components.

Level 3 builds on this to cover system repair and replacement, as well as more advanced electrical regeneration, rectification, and regulation skills. And for those that want to continue their training, the Level 4 course extends further into diagnostics, testing and advanced repairs.

The 2022 course schedule is open for bookings at www. Membership fees can be paid as a one off or as a 12-month direct debit. For more info, email

ZF Aftermarket Electric Vehicle Systems Training

The electric car market is growing quickly, with nearly 300,000 pure electric, battery-operated vehicles (BEV) cars on UK roads at the end of May 2021, and more than 600,000 plug-in models, if including plug-in hybrids (PHEVs).

More vehicles, both BEV and PHEVs, are out of warranty and reaching an age where owners want to have service and repairs carried out by independent garages. However, without the correct training, workshop employees are not allowed to touch an electric or hybrid vehicle by hand; a rule which even applies to simple maintenance work on conventional vehicle systems. In line with this, ZF Aftermarket has been working in conjunction with concerned industry parties including the Institute of Motor Industry (IMI) to lobby for increased communication of relevant training.

Make a date – the HVE way…

The High-voltage training, offered under the ZF [pro]Tech garage workshop concept, consists of coordinated e-learning and practical hands-on training for optimal learning success. To meet soaring demand for its HVE courses, the business is preparing to up the ante for 2022, promising to add further course dates to satisfy demand.

Training courses available:

Electrically Instructed Persons

For those who have been used to 12, 24 or 48V automotive electrical systems, a change in mindset and a higher level of awareness is needed to work safely with high voltage electric vehicles. For example, where electrical cables in a conventional vehicle are routinely removed and reinstalled multiple times and connections often tightened by feel, high voltage cables are only rated for a certain number of connection cycles and terminations must be accurately tightened to the specified torque. This is because any abrasion of the contact areas or incorrect tensioning can have a dramatic effect on their electrical resistance, possibly leading to localised heating and subsequent fire risk.

Blending theory and practical instruction, this IMI level 2 approved course imparts sufficient knowledge to take a delegate to the ‘Electrically Instructed Person’ (EIP) level of competence. Attendees learn fundamental safety procedures such as following vehicle manufacturers’ protocols for powering down a vehicle, and applying the correct techniques to ensure electrical isolation so that the vehicle cannot restart unintentionally. Each EIP course is one (admittedly long) day in duration and ideally has only eight delegates attending, allowing each person sufficient time to complete the practical exercises included.

High Voltage Experts

This is probably the most comprehensive level of electric vehicle systems training available in the UK, and is the same as that provided to ZF research and development staff and to certain vehicle manufacturers’ engineering teams and production line technicians.

While someone who achieves EIP status is well on the way to working safely with electric vehicles, they are not yet qualified to work on the high voltage parts of the system. To date, around a third of Electrically Instructed Persons have returned to tackle the advanced stage of ZF Aftermarket’s training offer: the ‘High Voltage Expert’ (HVE) level of competence, which also earns successful attendees the IMI level 3 qualification. Before gaining access to HVE training, applicants must pre-qualify by successfully completing six online e-learning modules during the six weeks prior to training.

The course is split across two weeks; three days per week plus an examination day. Week one covers the fundamental principles of electrical engineering. This takes candidates through Ohm’s law, power consumption and calculations on both series and parallel circuits using a combination of theoretical principles and practical examples. Week two puts this theory into practice, applying it to real world

Course Dates:
Electrically Instructed Persons (EIP) (1 day, IMI Level 2)
• 3rd March 2022
• 24th May 2022
• 30th June /2022
HVE (7-day IMI Level 3)
• 15th to 25th Feb 2022
• 3rd to 13th May 2022

Please get in touch ASAP to book, as places on these courses are determined by current Covid guidelines. Your name will be automatically added to a waiting list if no places are available and you will be informed of further dates in due course.


Porsche Cayenne 92A Hybrid brake vacuum issue

CASE STUDY: Opus IVS supports a customer with a Porsche Cayenne 92A Hybrid brake vacuum issue.

IVS 360, from Opus IVS, provides diagnostics and live repair guidance support services to help workshop technicians fix complex vehicles safely and fast. All Opus IVS mechanical repair solutions come with live repair guidance from IVS 360 OEM brand-specific master technicians.

Using the DrivePro’s diagnostic software and extensive product knowledge, the IVS 360 team identifies the cause and steps needed to fix vehicle faults. Support from the team can be requested directly from a DrivePro device or DrivePro Elite Diagnostic Kit.

Opus IVS’ experts remote in real time directly to vehicle communication systems to diagnose, program and calibrate vehicles. This eliminates the uncertainty, giving workshops the confidence to get the most complex vehicles back on the road safely and fast.

A recent case involved a Porsche Cayenne 92A 2011 model year. The vehicle had a hard brake pedal, which indicated a fault with the electrical vacuum when switching to Hybrid Drive. The IVS 360 team supported the customer with the following advice:

Make: Porsche

Model/Yr: Cayenne (2011 – 2017) Hybrid

Symptoms: Hard brake pedal

Example picture of Cayenne engine bay relay board.

The brake servo has a mechanical and electrical vacuum pump to create the required vacuum for the brake servo. When the vehicle switches to hybrid drive the electrical vacuum pump is used, or at a time the mechanical pump does not make required vacuum when the engine is running.

Fault codes: P147900 Brake boost vacuum system, mechanical failure DME – ENGINE ECU

The repair:

1. Connect your diagnostic tool and read out the fault codes

2. Checking the vacuum of the mechanical pump:

3. Check the vacuum pipes

The vacuum lines contain check valves, so be sure these are working. Check the vacuum lines for micro cracks. There are other vacuum systems for the control of the Secondary Air injection, intake manifold flaps. The solenoids (2 for Air injection, 1 for inlet manifold flaps) are mounted at the rear of the engine on a bracket. There is another vacuum line and solenoid for the engine coolant pump (water pump) shutoff slide control at the front of the engine.

4. The electric vacuum pump

The electrical pump is mounted lower on the engines side, near the front of Bank 1. The electrical pump is powered via a relay (3) in the under-bonnet fuse board, maxi fuse (4) provides the pump protection, the DME switches the relay depending on the pressure sensor reading. The pressure sensor is mounted in the vacuum line near to the brake servo.

5. Test the electrical vacuum pump

Check that the electrical vacuum pump runs and will create the required vacuum. Do this with engine off key on, the relay can be worked from the DME drive link function (or bridge relay) The DME only monitors the control of the relay not the pump electrical function.

6. Replace the electrical pump

If the electrical pump is determined to be faulty, i.e. not running (fuse and relay ok) noisy during operation, or is getting hot quickly, replace the electrical pump always together with the relay (3) and maxi fuse (4).

Tools required:

• Diagnostic tool

• Hand vacuum pump

• Smoke tester (optional)

For more information on Opus IVS diagnostic solutions and IVS 360, please visit

T: +44 (0) 1865 870 060 E: